The present invention relates to packages for protecting comestibles and to the materials from which such packages are made.
Presently there is a strong interest in the packaging industry for protecting comestibles, such as foodstuffs, medicines, and the like, by enveloping the substances in packages which are formed from various polymers. One polymer in which there is an especially strong interest is polyethylene terephthalate. Containers formed from this material, which may be biaxially oriented, possess many desirable characteristics. Molded biaxially oriented containers which are formed from polyethylene terephthalate and certain copolyesters are disclosed in U.S. Pat. No. 3,733,309. While containers formed from polyethylene terephthalate have many desirable characteristics, there is a need in the art to provide improved containers which will have gas permeabilities which are lower than those of containers formed from polyethylene terephthalate. Such improved containers would be much more versatile in their utilization and allow the containers to be used to package substances for which the polyethylene terephthalate containers may not be suitable.
The present invention provides a novel polymer blend which is suitable for use in forming packages for protecting comestibles. The present invention also provides improved containers made of the polymer blend which exhibit improved resistance to gas permeability.